1. Field of the Invention
This invention relates generally to devices for drawing, holding and dispensing liquids and more particularly to devices for simultaneously drawing, holding and dispensing a plurality of distinct liquid masses.
2. Description of the Prior Art
There are presently several devices available for drawing, holding and dispensing liquids. Such devices include medicine droppers, pipettes, capillary tubes, syringes, and the like. While these devices have been useful they have their disadvantages.
One particular problem with the devices utilized for dispensing liquids is accuracy. In devices which dispense small amounts of liquids the amount of wetted surface and droplet formation has been a problem in accurate dispensing. For example, if a droplet forms on the end of the dispensing device during the process of dispensing the device cannot be more accurate than the volume of the droplet formed. Gaps between moving parts of dispensing devices also can be a source of inaccuracy. For example, if an air space forms between the plunger of a syringe and the syringe wall when liquid is drawn up this air space prevents the syringe from dispensing more accurately than the volume of the air space. These same gaps can remain filled with a liquid when liquid is dispensed creating further inaccuracy.
Another problem with devices for drawing, holding and dispensing liquids has been that they are tedious to use. Thus, where liquid must be transferred to or from a number of liquid-containing wells, use of prior art devices can be extremely time consuming. This is especially true where accuracy of drawing and dispensing is required.
It is accordingly an object of the present invention to provide an improved device for drawing, holding and dispensing liquids and particularly such a device which can simultaneously draw, hold and dispense a plurality of distinct liquid masses. In this manner, simultaneous drawing, holding and dispensing liquid from an entire array of liquid containing wells can be achieved.
It is another object of the present invention to provide such an improved drawing, holding and dispensing device which has improved accuracy and is easy to use.
Still a further object of the invention is to provide such a drawing, holding and dispensing device which can be operated manually and particularly with a single hand.